This dataset is part of a large, trans-generational study investigating the role that manipulation of a neural pathway, specifically the pathway of the neurotransmitter dopamine, can have on behaviour and brain gene expression. To do this, we are manipulating dopamine with methylphenidate hydrochloride, a compound known to affect the dopaminergic system, and are comparing guppy brain gene expression between treated individuals and controls. We will then follow the descendants of both treated and control individuals to determine if manipulation of the dopaminergic has trans-generational, epigenetic effects on brain gene expression and behaviour. This project will allow us to better understand the effects of chronic exposure to this drug on the brain gene expression of the offspring of exposed individuals, and will allow us to better understand the role of non-genetic inheritance in general.